Variations have emerged to the simple direct wall mount system which includes a constructed frame that extends on the sides of the biofilter and eliminates the need for the finish trim on either end. This gives the biofilter more of a built-in look and defines the area for it to be located very clearly. Moving one step further, a recessed alcove can be provided in the design such that the sides and top of the biofilter are surrounded providing a fully built-in and permanent appearance.

In certain cases, it may be possible or desirable to incorporate a biofilter that is double sided and gives the appearance of being free-standing in a space. In this scenario, the plants are installed on both sides of the infrastructure or framework. This double sided approach not only provides the opportunity for more green plants in roughly the same footprint, it also can be designed to accommodate more air quantity and overall velocity as well.

Once the wall mounting is decided upon, the focus can turn to options for the water basin design at the bottom of the biofilter which acts as the catchment or reservoir for the water circulating in the system. As with the wall mounting, there are some choices here as well. The simplest approach is to build up the basin on top of the floor in the manner of a shower stall or other basin. The height of the basin can certainly vary a bit needing only to accommodate the amount of water needed for the system which may be inches deep and not necessarily feet. For design reasons, it may be desirable to extend the wall of the basin up anyway to prevent people from walking into it or tripping over it. Either way, the basin will need to be waterproofed to hold water just as a fountain or shower base would be. If the option exists to pour the sides of the basin using concrete at the same time that a concrete floor slab is poured, then that will help with the waterproofing and overall design as well.

An indoor air biofilter built into a recessed alcove appears more completely as a part of the building with a more permanent and finished look. Image courtesy of Nedlaw Living Walls Inc.

 

A variation on the simple basin design is to pursue greater integration into the design of the space. That could be done by raising the front edge up high enough to make it into a feature such as a sitting bench in front of the biofilter. Alternatively, the basin could be recessed or sunken into the floor so the bottom of the biofilter appears to be flush with the level of the floor.

The basin and water are necessary elements of an indoor air biofilter but can be visually incorporated by sinking the basin below the floor line. Image courtesy of Nedlaw Living Walls Inc.

 

In this case, it would be prudent to provide a safety surface under and in front of the plants that can still feed water into the basin. This surface might include filling it with small, smooth, round stone or covering it with an entrance style grating. In a different setting, full integration of a biofilter might include raising it up higher than the floor to allow it to pass over fixtures or openings for passageways. In this case, the catchment basin will need to be raised above these items, allow for drainage down to a larger water storage area and pumping. In this way, the raised catchment basin remains lighter in weight without the need for special structural supports. It is also possible that the drainage and pumps could be located on a different floor to allow for better integration and work around other building features.